Ichthyosis vulgaris (IV), a serious skin condition that runs in families, is actively studied worldwide. In this work we aimed to evaluate the prevalence of IV and frequency of two FLG mutations R501X and 2282del4 in the population of the Rostov region. Our genetic epidemiology study of hereditary monogenic disorders covered a total of 497,460 residents of 12 districts to identify 230 separate nosological entities. In the course of the analysis, we calculated the prevalence of IV per district and in the entire region and compared our findings with the results of earlier studies. The average prevalence of IV in the Rostov region was 1:5,025, which is consistent with the average prevalence of the disease across Russia (1:5,151). Tselinsky and Millerovsky districts demonstrated the highest prevalence rates (1:1,942 and 1:2,032, respectively). To evaluate the frequency of two FLG mutations R501X and 2282del4, we assayed the samples of 58 patients with IV and 127 healthy unelated controls by PCR followed by the restriction fragment length polymorphism analysis. In patients with IV, the frequency of the 2282del4 mutation was 48.28%, which is in line with European figures and also 30 times higher than in the controls (1.58%), suggesting the pathogenicity of the mutation. The R501X mutation was not identified both in patients with IV and healthy controls.